The present invention relates to a key-less entry system and the method thereof without inserting a key into a keyhole.
There are several types of the key-less entry systems for locking/unlocking vehicle doors without inserting the key into the keyhole.
One old type of the key-less entry system employs the key equipped with a lock button and an unlock button for locking/unlocking the vehicle doors by pressing the buttons.
On the other hand, an advanced key-less entry system, such as disclosed in Japanese Unexamined Patent Publication No. 61-5183, is equipped with a door-lock controller for locking/unlocking the vehicle doors by entering a cipher code.
In detail, the cipher code is entered by a combination of operations of a door outer handle and buzzer sounds. A door can be unlocked when the entered cipher code matches a prestored cipher code.
More in details, as illustrated in FIG. 1, the operation of a door outer handle is divided into several sequences by the buzzer sounds. FIG. 1 illustrates entering of a 4-digit cipher code “3431”. A buzzer goes off after a door outer handle is operated three times, which completes an entry of the first digit “3” of the 4-digit cipher code “3431”. In the same way, the second, the third and the fourth digit “4”, “3” and “1” of the 4-digit cipher code are entered. The signs “B” and “BB” in FIG. 1 indicate that the buzzer goes off one time and two times, respectively.
Since each of the four digits can be selected from among 10 digits “0” to “9”, there is 10000 (10×10×10×10) ways of the cipher code entry, which increases the number of operations of the door outer handle.